Overmolded wheel-balancing weight

ABSTRACT

A plastic wheel-balancing weight adapted to be removably secured to a wheel to correct an unbalanced wheel to prevent undesired vibrations when the wheel is rotating, the plastic wheel-balancing weight comprising a wheel-securing clip sized and designed to be resiliently secured to a wheel, and a steel weight assembled to the wheel-securing clip and at least partially covered with plastic, at least a portion of the plastic being shaped by the wheel-securing clip. An overmolded wheel-balancing weight comprising a wheel-securing clip adapted to be secured to a wheel, a weight assembled to the wheel-securing clip and overmolding material adapted to at least partially cover the weight to protect the weight, wherein at least a portion of the wheel-securing clip is an overmolding material boundary. A method of manufacturing same and a mold thereof is also provided.

CROSS-REFERENCE

This invention relates to and claim priority from U.S. provisionalpatent application No. 61/450,374, filed Mar. 8, 2011, entitled PLASTICOVERMOLDED WHEEL-BALANCING WEIGHT, which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

This invention relates to a method for covering and protecting a steelwheel-balancing weight. More precisely, the present invention relates topolymer-covered wheel-balancing weights, a method for manufacturing sameand a mold for manufacturing same.

BACKGROUND OF THE INVENTION

Wheel-balancing weights (or wheel weights, wheel balance weights) arecommonly used on wheeled vehicles to improve the static and dynamicbalancing of the wheel assembly. To balance the wheels, each wheel isrotated with a wheel-balancing apparatus that analyses and detectsuneven weight distribution thereof that could generate significantvibrations when the wheels rotate at various rotating speeds. Thisundesirable wheel vibration would be transmitted to the entire vehicle,if not corrected. Corrective wheel-balancing weights, when required, aresecured on the circumference of the wheel on both the interior and theexterior sides of the wheel. The addition of required wheel-balancingweights corrects the polar weight distribution of the wheel assembly andbalances the wheel that will rotate without inducing undesirablevibrations.

Legacy wheel-balancing weights are made in lead. Nowadays, environmentalconsciousness and regulations suggest avoiding using lead that couldhave an undesirable effect on our ecosystems. Replacement of lead bysteel is therefore a desirable direction.

However, the use of steel has some drawbacks. Steel is subject tocorrosion and should be protected thereagainst. Steel balancing weightscan also damage the wheel it is installed on. Steel is also harder andmore difficult to shape to obtain a close and precise fit between thewheel-balancing weight and the wheel it is secured thereto.Additionally, the aesthetic of steel wheel balancing weights isquestionable and it might be desirable to add a more visually attractivecover.

Covering the wheel-balancing weights with plastic could be anadvantageous alternative. However, molding plastic over thewheel-balancing weight requires a complex and expansive tooling. Issuescan arise when overmolding a steel wheel balancing weight. For instance,the overmolding plastic can retract and leave a gap with the steelweight where water and dirt can enter. Some overmolding materials mightdifficultly manage frequent changes in temperature and react poorly toimpacts thereon. The geometry of the plastic overmolding might alsorequire complex and expansive molds and handling.

The junction between the overmolding material and the wheel-securingclip is a sensitive portion of the overmolded wheel-balancing weightbecause the overmolding material boundary merges with the wheel-securingclip generally made of a different material.

Therefore, there exists a need in the art for an improved method, systemand apparatus for covering wheel-balancing weights with plastic, polymeror another material. There is a need in the art for such a method,system and apparatus for covering wheel-balancing weights withovermolding polymer or another material that can be easily installed,economically manufactured and operated. And there is a very perceptibleneed for an improved fit between a polymer-covered wheel-balancingweight and a method of manufacturing same over the existing art.

SUMMARY OF THE INVENTION

It is one aspect of the present invention to alleviate one or more ofthe drawbacks of the background art by addressing one or more of theexisting needs in the art.

Accordingly, at least one embodiment of the invention provides anundercutless overmolded wheel-balancing weight, a mold for producingsame and a method of overmolding a steel wheel-balancing weight adaptedto prevent injecting overmolding material in the region of theoverhanging wheel-securing clip.

At least one embodiment of the invention provides a method ofovermolding a metallic wheel-balancing weight using a mold that preventspolymer injection around the wheel-securing clip that would create anundercut interfering with the ejection of the overmolded wheel-balancingweight from the mold and require a more complex mold adapted to manageoverhanging portions.

At least one embodiment of the invention provides a method and anapparatus for overmolding a steel wheel-balancing weight with a polymerwherein the distribution of polymer around the wheel-balancing weightallows extraction of the overmolded wheel-balancing weight by simplyopening the apparatus in two.

At least one embodiment of the invention provides a method and a moldfor overmolding a wheel-balancing weight with a polymer wherein thedistribution of polymer around the wheel-balancing weight allowsextraction of the overmolded wheel-balancing weight by opening the moldin two along the longitudinal plan of the wheel-balancing weight.

At least one embodiment of the invention provides ribs disposed on thelongitudinal sides of the overmolded wheel-balancing weight that helpmaintains the wheel-balancing weight on one halve of the mold tofacilitate extraction of the overmolded wheel-balancing weight whenopening the mold in two halves along the longitudinal plan of thewheel-balancing weight.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight with a polymerwherein the distribution of polymer around the clip of thewheel-balancing weight allows extraction of the overmoldedwheel-balancing weight by opening the mold in two halves along thelongitudinal plan of the wheel-balancing weight.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight with a polymerwherein the clip of the wheel-balancing weight substantially follows theshape of the overmolding polymer.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight with a polymerwherein the clip of the wheel-balancing weight substantially angularlyextends from the overmolded polymer to offer a tight polymer-clipjunction.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight with a polymer-freewheel-balancing weight clip area.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight while preventingpolymer to be injected around the clip that would prevent removal fromthe mold by opening the mold in two.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight that uses thewheel-securing clip of the wheel-balancing weight for restricting theinjection of polymer around the wheel-securing clip.

At least one embodiment of the invention provides a method and anapparatus for overmolding a wheel-balancing weight that reduces thethickness of the overmolding material in the area surrounding thewheel-securing clip of the wheel-balancing weight.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight that has no undercuts created by the overhangingwheel-securing clip assembled thereto.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight having no polymer within the cavity defined bythe wheel-securing clip and a method of manufacturing same.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight wherein the overmolding material follows theshape of the wheel-securing clip of the wheel-balancing weight thatsubstantially define the shape of at least a portion of the overmoldingpolymer.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight wherein an edge of the overmolding materialradially meet the wheel securing clip of the wheel-balancing weight.

At least one embodiment of the invention provides a wheel-securing clipconfigured to secure a wheel-balancing weight to a wheel, wherein thewheel-securing clip includes a raised portion adapted to improve thejunction between an edge of the overmolding material and thewheel-securing clip.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight wherein the wheel-securing clip of thewheel-balancing weight substantially contacts the injection mold andforms an injection boundary portion of the injection mold.

At least one embodiment of the invention provides a polymer overmoldedwheel-balancing weight having a shape adapted to substantially match thecircumference of the wheel secured thereto.

At least one embodiment of the invention provides an overmoldedwheel-balancing weight wherein the weight is secured to thewheel-securing clip on the side opposed to the wheel-side when theovermolded wheel-balancing weight is secured to a wheel.

At least one embodiment of the invention provides an overmoldedwheel-balancing weight that connects the weight to the wheel-securingclip via a protrusion formed in the weight; the protrusion being adaptedto be compressed and/or riveted to secure the wheel-securing cliptherewith.

At least one embodiment of the invention provides a wheel-securing clipfor securing an overmolded wheel-balancing weight to a wheel thatincludes a recessed weight-securing portion sized and designed toreceive therein material from a compressed protrusion protruding fromthe weight.

At least one embodiment of the invention provides a method ofmanufacturing an overmolded wheel-balancing weight, wherein thewheel-securing clip is used to locate the wheel-balancing weight in themold; the wheel-balancing weight being preferably secured on the fixedportion of the mold.

At least one embodiment of the invention provides a method ofmanufacturing an overmolded wheel-balancing weight, wherein thewheel-balancing weight is secured in the mold with a clip-securingmember adapted to pull the wheel-balancing weight with a moveable sideof the mold.

At least one embodiment of the invention provides a method ofmanufacturing an overmolded wheel-balancing weight, wherein theovermolding material and/or the wheel-balancing weight is preheated toprevent expedite solidification of the injected overmolding material.

At least one embodiment of the invention provides a method ofmanufacturing an overmolded wheel-balancing weight, wherein theovermolding material is injected nearby the wheel-securing clip toequally distribute the overmolding material in the injection cavity ofthe injection mold.

At least one embodiment of the invention provides a colored polymerovermolded wheel-balancing weight adapted to substantially match thecolor of the wheel it is secured to.

At least one embodiment of the invention provides a kit of coloredovermolded wheel-balancing weights wherein colors are adapted todistinguish wheel-balancing weights different having different weights.

At least one embodiment of the invention provides an injection moldincluding at least one retractable stem therein adapted to locate theweight in the injection mold during the injection of the overmoldingmaterial in the injection chamber, the at least one retractable stembeing further adapted to be retractable during the injection process toallow complete overmolding of the weight, the at least one retractablestem also being adapted to be extended to locate and eject theovermolded wheel-balancing weight from the injection mold.

At least one embodiment of the invention provides a polymer (or plastic)weight (e.g. steel less weight) supported by a wheel-securing clip, thepolymer weight being molded with the wheel-securing weight, the polymerweight being desirable for lightweight wheel-balancing masses that donot require a metallic weight.

At least one embodiment of the invention provides an overmoldedwheel-balancing weight comprising a wheel-securing clip adapted to besecured to a wheel, a weight assembled to the wheel-securing clip andovermolding material adapted to at least partially cover the weight toprotect the weight, wherein at least a portion of the wheel-securingclip is an overmolding material boundary.

At least one embodiment of the invention provides a method ofmanufacturing an overmolded wheel-balancing weight, the methodcomprising opening an injection cavity of an injection mold; securingthe wheel-securing clip to a clip-supporting member in the mold tolocate a weight in the injection cavity; closing the injection mold witha weight in the injection cavity; injecting overmolding material in theinjection cavity to overmold at least a portion of the weight; openingthe mold; and extracting the overmolded wheel-balancing weight from themold.

At least one embodiment of the invention provides a plasticwheel-balancing weight adapted to be removably secured to a wheel tocorrect an unbalanced wheel to prevent undesired vibrations when thewheel is rotating, the plastic wheel-balancing weight comprising awheel-securing clip sized and designed to be resiliently secured to awheel; and a steel weight assembled to the wheel-securing clip and atleast partially covered with plastic, at least a portion of the plasticbeing shaped by the wheel-securing clip.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description givenhereinafter. However, it should be understood that the detaileddescription and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art from thisdetailed description.

Additional and/or alternative advantages and salient features of theinvention will become apparent from the following detailed description,which, taken in conjunction with the annexed drawings, disclosepreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings which form a part of this originaldisclosure:

FIG. 1 is a top plan view of an overmolded wheel-balancing weight inaccordance with at least one embodiment of the invention;

FIG. 2 is a flow chart illustrating a series of steps to produce anovermolded wheel-balancing weight in accordance with at least oneembodiment of the invention;

FIG. 3 is a flow chart illustrating a series of steps to produce anovermolded wheel-balancing weight in accordance with at least oneembodiment of the invention;

FIG. 4 is an almost front elevational view of an overmoldedwheel-balancing weight in accordance with at least one embodiment of theinvention;

FIG. 5 is a front elevational view of an overmolded wheel-balancingweight in accordance with at least one embodiment of the invention;

FIG. 6 is a top plan view of an overmolded wheel-balancing weight inaccordance with at least one embodiment of the invention;

FIG. 7 is a rear sectional elevational view of an overmoldedwheel-balancing weight in accordance with at least one embodiment of theinvention;

FIG. 8 is a front sectional elevational view of an overmoldedwheel-balancing weight in accordance with at least one embodiment of theinvention;

FIG. 9 is a transversal isometric sectional elevational view of anovermolded wheel-balancing weight in accordance with at least oneembodiment of the invention;

FIG. 10 is a transversal sectional elevational view of an overmoldedwheel-balancing weight in accordance with at least one embodiment of theinvention;

FIG. 11 is an isometric view of an overmolded wheel-balancing weight inaccordance with at least one embodiment of the invention;

FIG. 12 is a transversal sectional view of an overmolded wheel-balancingweight in accordance with at least one embodiment of the invention;

FIG. 13 is an isometric view of a wheel-securing clip in accordance withat least one embodiment of the invention;

FIG. 14 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 15 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 16 is left side elevational view of a wheel-securing clip inaccordance with at least one embodiment of the invention;

FIG. 17 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 18 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 19 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 20 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 21 is a transversal sectional elevational view of a wheel-securingclip in accordance with at least one embodiment of the invention;

FIG. 22 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 23 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 24 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 25 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 25 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 26 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 27 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 28 is a transversal sectional elevational view of a wheel-securingclip and a weight of an overmolded wheel-balancing weight in accordancewith at least one embodiment of the invention;

FIG. 29 is an isometric view of a wheel-securing clip and a weight of anovermolded wheel-balancing weight in accordance with at least oneembodiment of the invention;

FIG. 30 is an isometric view of a wheel-securing clip and a weight of anovermolded wheel-balancing weight in accordance with at least oneembodiment of the invention;

FIG. 31 is an isometric view of a portion of an injection mold inaccordance with at least one embodiment of the invention;

FIG. 32 is a side elevation view of a portion of an injection mold inaccordance with at least one embodiment of the invention;

FIG. 33 is an isometric view of a portion of an injection mold inaccordance with at least one embodiment of the invention;

FIG. 34 is an illustrative flow chart of an exemplary series of steps inaccordance with at least one embodiment of the invention; and

FIG. 35 is an illustrative flow chart of an exemplary series of steps inaccordance with at least one embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the present invention are described bellow with referenceto the appended Figures. An exemplary overmolded metallicwheel-balancing weight 10 is illustrated in FIG. 1. The wheel-balancingweight 10 defines, for the purpose of the following description, atleast two illustrative plans thereof. A longitudinal plan 14 disposedalong the longitudinal direction of the wheel-balancing weight 10 and atransversal plan 18 orthogonally intersecting the longitudinal directionof the wheel-balancing weight 10. It is understood that the presentinvention can be completely or partially applied to a variety ofwheel-balancing weights 10 having various sizes and shapes.

The illustrative wheel-balancing weight 10 depicted in FIG. 1 isovermolded with an polymer overmolding material such as polyethylene andpolypropylene. The overmolding material 22 overmolds and protects thesteel weight 26 therein against, inter alia, water, corrosion, dust andother debris encountered on the road. The overmolding material alsoservers to protect the wheel form the wheel-balancing weight 10 duringinstallation on the wheel and when the wheel-balancing weight 10 isinstalled on the wheel under normal road use. Additionally, theovermolding material is used to improve the aesthetic appearance of thewheel-balancing weight and be used to visually differentiate differentweights.

A wheel-securing clip 30 is secured to the overmolded steel weight 26 toremovably secure the wheel-balancing weight 10 to the periphery of awheel (not shown). An optional hole 34 is performed in thewheel-securing clip 30 in some embodiments to adjust the clipping forceof the wheel-securing clip 30 on the wheel, provide a grip to remove thewheel-balancing weight 10 from the wheel and/or reduce the weight of thewheel-balancing weight 10. The hole 34 is also used in some embodimentsof the manufacturing process to handle the wheel-balancing weight 10 asit is going to be further explained below. Radiuses 38, or chamfers 38,are provided on ends corners of the wheel-securing clip 30 to preventcreating stress concentrators in the overmolded polymer that couldresult in rupturing the overmolded polymer and create cracks therein.The radiuses 38, or chamfers 38 also help prevent damaging the wheelwith sharp edges if used without overmolding. Embodiments of the presentinvention includes a reduced thickness portion 42 of the overmoldedmaterial 22, in the neighborhood of the wheel-securing clip 30, toprevent interferences between the overmolding material 22 and thewheel-securing clip 30. The portion 42 thus facilitate proper connectionbetween the wheel-securing clip 30 and the wheel and prevents anyovermolding material 22 to be injected within the cavity defined by thewheel-securing clip 30 that would render harder the ejection of thewheel-balancing weight 10 from the mold. We will return later to themanufacturing aspects of the wheel-balancing weight 10 after somedetails concerning process embodiments for manufacturing thewheel-balancing weight 10.

FIG. 2 illustrates an exemplary series of manufacturing steps adapted toproduce a wheel-balancing weight 10. An unmolded steel weight 26 isprovided from raw material, preferably in the shape of a steel rod 50, asteel wire 50, or similar monolithic steel weight 26 adapted to improvewheel balancing. The raw steel rod is cut 54 and the length of the cutportion of steel rod 50 is determined by the desired weight of thewheel-balancing weight 10. The total mass of the wheel-balancing weight10 is equal to the added weight of the wheel-securing clip 30, the steelweight 26 and the overmolding material 22. The longer the portion of cutsteel rod 50 is, the heavier the wheel-balancing weight 10 is going tobe. Chamfers or radiuses are optionally performed 58 on each end of thesteel weight 26 to remove undesirable sharp edges. The steel weight 26is then stamped 62 to create therein a fastening protrusion 128 and anoptional opposed compressed portion 140 that will be described indetails below. The steel weight 26 is optionally plated after it hasbeen chamfered and/or bent to improve, inter alia, its corrosionresistance 66. A wheel-securing clip 30 is assembled 70 with thecorresponding fastening protrusion and the wheel-securing clip 30 issecured to the steel weight 26 by compressing and deforming thefastening protrusion 74 to secure the wheel-securing clip 30 to thesteel weight 26. The assembled wheel-balancing weight 10 is then bent 78to match the radius of the wheel it is going to be assembled to. Thesteps above are for illustrative purposes and can be reordered withoutdeparting from the scope of the present application.

FIG. 3 illustrates another exemplary series of steps for manufacturingpolymer-overmolded wheel-balancing weights 10 in accordance withembodiments of the invention. An unmolded wheel-securing clip 30 andsteel weight 26 assembly is inserted in an injection mold 90. The moldis closed 94 to define a volume therein (e.g. injection chamber) forinjecting a polymer, a resin, a thermoset plastic, a plastic or anothersuitable overmolding material around the unmolded wheel-securing clip 30and steel weight 26 assembly. The connection between the wheel-securingclip 30 and the mold could be used to locate the steel weight 26 insidethe mold. Polymers, such as polypropylene and polyethylene, could beused in the process. A precise fit is provided between the mold and thewheel-securing clip 30 to prevent any injection of plastic at undesiredlocations around the wheel-securing clip 30. The mold interface with thewheel-securing clip 30 is designed in embodiments of the invention toprevent any undercuts that would interfere with the ejection of themolded wheel-balancing weight 10 with a mold having two halves and asingle longitudinal parting line. Polymer is injected 98 in the mold andthe injected plastic is cooled 102 prior to opening the mold 106 andextracting 110 the overmolded wheel-balancing weight from the mold.

FIG. 4 through FIG. 10 refer to an exemplary embodiment of theinvention. More precisely FIG. 4 through FIG. 6 depict the exterior ofthe wheel-balancing weight 10 where it is possible to see the polymerovermolding 22, the parting line 120, and the wheel-securing clip 30extending outside the polymer overmolding 22.

FIG. 7 and FIG. 8 respectively illustrate longitudinal sectional viewsof the wheel-balancing weight 10 where one can appreciate a compressedportion 124 in the steel weight 26 from which extends the fasteningprotrusion 128. The fastening protrusion 128 is assembled with acorresponding opening 132 located in the clip 30. The illustratedassembly secures the wheel-securing clip 30 with the steel weight 26 bybending or compressing the fastening protrusion 128 when thewheel-securing clip 30 is assembled thereto. It can also be appreciatedfrom these Figures that the steel weight 26 of the wheel-balancingweight 10 is curved along a radius 136. The optional opposite compressedportion 140 can be appreciated on the other side of the steel weight 26illustrated in FIG. 8. The opposite compressed portion 140 helps toensure proper pressure is put on the steel weight 26 at the stampingphase to create the fastening protrusion and also increases the strengthof the steel weight 26 by locally hardening the material. The materialof the protrusion 128 is adapted to be housed by a recessed portion 188of the wheel-securing clip 30 that will be detailed later below.

Turning now to FIG. 9 where the fastening protrusion 128 assembly withthe corresponding opening 132 located in the clip 30 is illustrated withmore details. From this figure it can be appreciated that the mold(visible schematically illustrated in FIG. 10) design circumscribes theclip 30 and that results in no plastic injection within the clip 30cavity 144. Further, the shape of the clip 30 defines a radius 148 thatretains the injected plastic on its proximal side 156 when the plasticis injected and abuts the plastic portion of the wheel-balancing weight10 when the wheel-balancing weight 10 is overmolded. This layout allowsovermolding the fastening protrusion 128 and the assembly with the clip30 with plastic thus improving its corrosion resistance while reducingthe risk of damaging the wheel when the wheel-balancing weight 10 isassembled to the wheel. FIG. 10 illustrates an exemplary mold having twohalves 160, 164 circumventing the wheel-securing clip 30 while defininga closed volume around the steel weight 26 to receive injected plastictherein. It can be appreciated that the shape of the mold's halves 160,164 is adapted to use the wheel-securing clip 30 as a mold boundary andthus prevent plastic to be injected too far within the cavity defined bythe clip 30. This is one way to ensure there is no undercut in themolding that would prevent extraction of the molded part 10 from a moldhaving two halves 160, 164 and opening in the longitudinal plan 14 ofthe wheel-balancing weight 10. In an alternate embodiment, the clip 30can be completely free of plastic. Plastic is injected all around theclip 30 and even leaves the region of the clip that is connected withsteel weight 26 free of plastic. Conversely, it could be advantageous tocover the connecting region between the clip 30 and the steel weight 26with plastic to further prevent corrosion.

Moving now to FIG. 11 and FIG. 12 illustrating another embodiment of theinvention. One can appreciate from FIG. 11 that the clip 30 has adifferent radius 148 causing the clip 30 to protrude almostperpendicular from the plastic molding 22. As best seen in FIG. 12, thepresent assembly allows sufficient distance 152 between the clip 30 andthe polymer overmolding 22 to insert therein a portion of the moldadapted to mate with the clip 30 and prevent plastic injection aroundthe clip 30 that would prevent a two halves 160, 164 mold to be openedin the longitudinal plane 14 and the wheel-balancing weight 10 to beeasily extracted from the mold. In the present situation, a schematictwo-halves 160, 164 mold with a single longitudinal opening therein hasbeen drafted showing that the wheel-balancing weight 10 can be ejectedfrom the mold that opens in two according to arrows 170.

FIG. 13 illustrates a wheel-securing clip 30 equipped with a barb 174adapted to further secure the wheel-securing clip 30 to a wheel byproviding additional gripping to the wheel. The barb 174 of the presentembodiment provides a second spring clamping 180 for gripping the wheelin addition to the first spring clamping 184 provided by the main bodyof the wheel-securing clip 30. The shape of the wheel-securing clip 30is adapted to engage the side of a wheel and is also adapted to besecured to the steel weight 26. The interface between the wheel-securingclip 30 and the steel weight 26 has generally been described above. Thewheel-securing clip 30 illustrated in FIG. 13 is provided with arecessed portion 188 sized and designed to receive therein material fromthe compressed fastening protrusion 128 (not illustrated in FIG. 13)engaging the opening 132 in the wheel-securing clip 30. The opening 132can be round or have a different shape adapted to prevent relativerotation of the two parts. The recessed portion 188 would preferably bedeep enough to receive therein the material from the compressedfastening protrusion 128 so that it does not extend above thesurrounding surface 192. This helps reduce the required thickness ofovermolding material 22 (not illustrated on FIG. 13) over the “riveted”assembly of the wheel-securing clip 30 and the steel weight 26.

Another aspect of the wheel-securing clip 30 illustrated in FIG. 13 isthe recessed position of the surface 192 provided by the deportingportion 196 included in the design of the wheel-securing clip 30. Thedeporting portion 196 is embodied as a curved portion 200 in the presentexample. The curved portion 200 defined in the wheel-securing clip 30locate the surface 192 deeper so that the overmolding material 22 canmeet the curved portion 200 in a way to produce an efficient junction.This can be better understood by comparing a wheel-securing clip 30having no deporting portion 196, in FIG. 14, and the wheel-securing clip30 of FIG. 13 illustrated from the side in FIG. 15. One can appreciatethat the curved portion 200 provides a junction area 204 adapted to abutthe overmolding material 22 that is schematically represented in FIG.15. The junction area 204 created by the curved portion 200 defined inthe deporting portion 200 is adapted to abut the overmolding material22. The curved portion 200 can be used as an extension of the mold andis used to further define the volume defined by the mold. The curvedportion 200 provides a more “radial” junction surface with theovermolding material 22. This prevents having a very thin layer ofovermolding material 22 joining the wheel-securing clip 30 that couldeasily wave or curve and leaves an opening for dirt and water to enterbetween the overmolding material 22 and the wheel-securing clip 30. Insome embodiments, the desired thickness 208 of overmolding material 22over the surrounding surface 192 can dictate the height of the curvedportion 200 therefore many different designs are possible to servedifferent needs. A second junction area 212 is provided on the oppositeside and preferably provides a surface that can substantially radiallyabuts the overmolding material 22. As it can be appreciated, a wholeportion 216 of the wheel-securing clip 30 is used to contain theovermolding material 22.

FIG. 16 through FIG. 21 illustrate a series of embodiments includingwheel-securing clips 30 having different shapes adapted to be secured todifferent shape of wheels and adapted to cooperate with various metallicweights 26. For example, the embodiments illustrated in FIG. 13, FIG.15, FIG. 17, FIG. 18 and FIG. 20 respectively have a flat clip portion220. FIG. 19 illustrates an embodiment including an angled flat clipportion 224.

Turning now to FIG. 22 through FIG. 25 illustrating a series ofsectional embodied wheel-balancing weights 10. In these embodiments thesteel weight 26 is assembled to the wheel-securing clip 30 but thefastening protrusion 128 is not shown compressed. From these embodimentsone can appreciate the distribution of the overmolding material 22 overthe steel weight 26. The contact locations 230 between the steel weight26 and the wheel-securing clip 30 is clearly shown for each embodiment.FIG. 22 illustrate en embodiment corresponding to the wheel-securingclip 30 of FIG. 14 that does not include a deporting portion 196. Theembodiments shown in FIG. 15 through FIG. 27 include the deportingportion 196 that allows an additional thickness 208 of overmoldingmaterial 22. It can be appreciated from FIG. 23 through FIG. 27 that thecombination of the deporting portion 196 and the recessed portion 188 ofthe wheel-securing clip 30 create a sequence of three combined curves234 (or combined angled portions). A portion of a stamping 46, or ashape/letters/information, defined in the overmolding material 22 canalso be seen in these figures.

Referring to FIG. 22, the steel weight 26 is provided with flat, orplanar, contact portions 238 adapted to provide a suitable contactinterface with the wheel-securing clip 30. Radiuses 242 are provided onthe metallic weights 26 to substantially match the curvature of the clip148 in some embodiments and also provide a space where overmoldingmaterial 22 can be injected between the wheel-securing clip 30 and themetallic-weight 26.

The wheel-securing clip 30 is secured to the steel weight 26 via theinterface provided between the fastening protrusion 126 engagement withthe opening 132 provided in the wheel-securing clip 30. The fasteningprotrusion 126 is compressed 250 to protrude and extend 254 over therecessed portion 188 of the wheel-securing clip 30 as it can beappreciated in FIG. 28, FIG. 29 and FIG. 30. This assembly ensures thatthe wheel-securing clip 30 is permanently secured to the steel weight 26to create a unitary wheel-balancing weight 10.

The overmolded-wheel balancing weight 10 of embodiments of the inventionis manufactured with an injection process. The injection process uses amold 270 including a fixed portion 274 and a movable portion 278 thatcan be appreciated in FIG. 31 through FIG. 33. The wheel-securing clip30 and steel weight 26 assembly is positioned in the mold 270 prior toinjecting the polymer in the mold 270. The wheel-securing clip 30 andsteel weight 26 assembly is located in the mold 270 by hooking thewheel-securing clip 30 to a clip supporting member 282 when the mold 270is open. The wheel-securing clip 30 is preferably self-positioned bycontacting the clip supporting member 282 at a plurality of locations.In the embodiment exemplified in FIG. 32, the end 286 of thewheel-securing clip 30 contacts the upper side 290 of the clipsupporting member 282 while a lower portion 216 of the wheel-securingclip 30 contacts the lower side 294 of the clip supporting member 282.Further, the end 286 of the wheel-securing clip 30 is contacting avertical edge 298 of the mold 270 to ensure not lateral movement isallowed. The clip-supporting member 282 of the illustrated embodiment isdefined in the fixed portion 274 of the mold 270 with a clip-receivingcavity 302 included in the mold 270. The clip-receiving cavity 302 isprolonging a clip-retaining member cavity 306 in the movable portion 278of the mold 270 from which extends a movable clip-retaining member 310that will be discussed below in details.

The wheel-securing clip 30 is temporarily secured in the mold 270 whenthe movable portion 278 of the mold 270 is closed onto the fixed portion274 by applying a pressure on the wheel-securing clip 30 with a clipmating edge 314. With that configuration, the wheel-securing clip 30 andsteel weight 26 assembly is positioned such that the wheel-securing clip30 is firmly secured in the closed mold 270 and the steel weight 26 issuspended in the injection cavity 318 of the mold 270. Injection of theovermolded material is preferably made symmetrically in the injectioncavity 318. In the illustrated embodiment, the injection is made througha central injection port 322 to ensure equal distribution of theinjection material 22 in the injection cavity 318. Alternatively, theinjection could be made by a plurality of injection ports (notillustrated) that would also equally distribute the injection material22 in the injection cavity 318. The steel weight 26 can be preheatedprior to be placed in the injection cavity 318 to help prevent expeditedsolidification of the injection material 22 by cooling too fast theinjection material 22 in the mold 270 such that the injection material22 doesn't have time to fill completely the injection cavity 318 beforesolidification. Another way to help prevent early solidification of theinjection material 22 is to preheat the injection material 22 in thecircuit bringing the injection material 22 in the mold 270 to increasethe time before the injection material 22 begins solidification.Positioning stems 338 (visible in FIG. 33) are provided in the mold 270to help locate properly the steel weight 26 in the injection cavity 318.These positioning stems 338 are adapted to be axially movable forcontacting the metallic weight 22 when the mold 270 is closed and ensureproper positioning of the metallic weight 22. The positioning stems 338are adapted to be retracted as some point during the injection processwhen the overmolding material 22 begins to flow in the injection cavity318. The positioning stems 338 becomes optional when the overmoldingmaterial 22 is injected in the injection cavity 318 because theovermolding material 22 stabilizes the steel weight 26 in the injectioncavity 318. The injection of the overmolding material 22 is completedwhen the positioning stems 338 are retracted to ensure an even finish ofthe overmolding material 22. The stems 338 are extended again, in anembodiment of the invention, when the mold 270 opens to stabilize andeject the overmolded wheel-balancing weight 10 from the mold 270.

The movable clip-retaining member 310 is engaging the hole 34 includedon the upper side of the wheel-securing clip 30 when the mold 270 isclosing. The movable clip-retaining member 310 extends from theclip-retaining cavity 306 in the movable portion 278 of the mold 270.The clip-retaining cavity 306 is sized and designed to allow sufficientvertical movements 326 to allow engagement of the hook 330 with the hole34. A corresponding opening 334 is included in the fixed portion 274 ofthe mold 270. The corresponding opening 334 is configured to receivetherein the movable clip-retaining member 310 and also to push themovable clip-retaining member 310 downward so that the hook 330 engagesin the hole 34 of the wheel-securing clip 30 and cannot disengage whenthe mold 270 is closed. The movable clip-retaining member 310 is used topull the overmolded wheel-balancing weight 10 from the fixed portion 274of the mold 270 as it can be seen in FIG. 33. Once the overmoldedwheel-balancing weight 10 pulled from the fixed portion 274 of the mold270 the movable clip-retaining member 310 is moved upward to disengagethe movable clip-retaining member 310 from the hole 34 of thewheel-securing clip 30.

Referring now more precisely to FIG. 33, the illustrated overmoldedwheel-balancing weight 10 has no overmolding material 22 in theneighborhood of the wheel-securing clip 30 to better see the assembledovermolded wheel-balancing weight 10 and also to illustrate oneembodiment of the invention. In contrast, the junction of thewheel-securing clip 30 with the steel weight 26 is covered in otherembodiments discussed above.

FIG. 34 illustrates an exemplary sequence of steps that can be used toovermold a wheel-balancing weight 10. The mold 270 opens 350, the steelweight 26 is heated 354 to prevent early solidification of theovermolding material 22, The wheel-securing clip 30 is secured 358 inthe mold 270, the mold is closed 362 and the wheel-securing clip 30 issecured in the mold 270, the polymer, or the overmolding material, isheated 366 prior to be injected in the mold 270, the polymer is injected370 in the mold 270 and solidifies, the mold 270 opens 374 to extractthe overmolded wheel-balancing weight 10 therefrom 374, the hook 330from the movable clip-retaining member 310 is released 378 from thewheel-securing clip 30 and finally the overmolded wheel-balancing weight10 is released 382 from the mold 270.

Similarly, FIG. 35 illustrates another alternate sequence of stepsadapted to embody embodiments of the invention. The wheel-securing clip30 is used to locate 390 the unmolded steel weight 26 in the mold 270,The mold 270 is closed and the hook 330 engages 394 the wheel-securingclip 30, the overmolding material is heated 398 prior to being injectedin the mold 270, the overmolding material 22 is injected in the mold'sinjection cavity 318, the locating stems 338 are retracted 406 duringinjection of the overmolding material 22 in the injection cavity 318,the injection stops 410, the mold 270 opens 414 and the overmoldedwheel-balancing weight 10 is extracted 418 from the mold 270.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments and elements, but, to the contrary, is intended tocover various modifications, combinations of features, equivalentarrangements, and equivalent elements included within the spirit andscope of the appended claims. Furthermore, the dimensions of limiting,and the size of the components therein can vary from the size that maybe portrayed in the figures herein. Thus, it is intended that thepresent invention covers the modifications and variations of theinvention, provided they come within the scope of the appended claimsand their equivalents.

1. An overmolded wheel-balancing weight comprising: a wheel-securingclip adapted to be secured to a wheel; a weight assembled to thewheel-securing clip; and overmolding material adapted to at leastpartially cover the weight to protect the weight, wherein at least aportion of the wheel-securing clip is an overmolding material boundary.2. The wheel-balancing weight of claim 1, wherein the at least a portionof the wheel-securing clip is adapted to mold a portion of theovermolding material when the overmolding material is injected.
 3. Thewheel-balancing weight of claim 1, wherein the wheel-securing clipincludes a cavity adapted to mate with a portion of a wheel to securethe overmolded wheel-balancing weight to the wheel and wherein thecavity is free of overmolding material.
 4. The wheel-balancing weight ofclaim 1, wherein the wheel-securing clip includes a deporting portionand a recessed portion, wherein the overmolding material abuts thedeporting portion.
 5. The wheel-balancing weight of claim 1, wherein theovermolding material is a polymer.
 6. The wheel-balancing weight ofclaim 5, wherein the polymer includes one of polyethylene andpolypropylene.
 7. The wheel-balancing weight of claim 1, wherein theweight includes steel material.
 8. The wheel-balancing weight of claim1, wherein the weight includes a protrusion adapted to connect thewheel-securing clip.
 9. The wheel-balancing weight of claim 8, whereinthe wheel-securing clip includes a recessed portion adapted to receivetherein a portion of the protrusion to assemble the weight to thewheel-securing clip.
 10. A method of manufacturing an overmoldedwheel-balancing weight, the method comprising: opening an injectioncavity of an injection mold; securing the wheel-securing clip to aclip-supporting member in the mold to locate a weight in the injectioncavity; closing the injection mold with a weight in the injectioncavity; injecting overmolding material in the injection cavity toovermold at least a portion of the weight; opening the mold; andextracting the overmolded wheel-balancing weight from the mold.
 11. Themethod of claim 10, wherein the injection mold is a two halves injectionmold adapted to be opened in a longitudinal plan of the wheel-balancingweight.
 12. The method of claim 10, wherein the injection mold isadapted to produce an undercutless overmolded wheel-balancing weight.13. The method of claim 10, wherein the injection mold includes awheel-securing clip retaining member adapted to unsecure thewheel-securing clip from the clip-supporting member when the mold opens.14. The method of claim 13, wherein the wheel-securing clip retainingmember is adapted to engage an upper portion of the wheel-securing clip.15. The method of claim 13, wherein the injection cavity is providedwith at least one stem adapted to further locate the weight in theinjection cavity and wherein the at least one stem is adapted to beaxially movable during injection of overmolding material in theinjection chamber.
 16. The method of claim 10, wherein thewheel-securing clip-retaining member is disposed on a non-movable halveof the injection mold.
 17. The method of claim 10, wherein thewheel-securing clip is adapted to be an extension of the injectioncavity adapted to define a shape of the overmolding material.
 18. Aplastic wheel-balancing weight adapted to be removably secured to awheel to correct an unbalanced wheel to prevent undesired vibrationswhen the wheel is rotating, the plastic wheel-balancing weightcomprising: a wheel-securing clip sized and designed to be resilientlysecured to a wheel; and a steel weight assembled to the wheel-securingclip and at least partially covered with plastic, at least a portion ofthe plastic being shaped by the wheel-securing clip.
 19. The plasticwheel-balancing weight of claim 18, wherein the weight includes a radiusof curvature adapted to substantially match a radius of curvature of thewheel.
 20. The plastic wheel-balancing weight of claim 18, wherein theat least a portion of the plastic being shaped by the wheel-securingclip is further shaped by a deporting portion included in thewheel-securing clip.